B4 mount lenses would need correction?

[Sebastian Cramer]

It's absolutly great that the red is offering different lens mounts, I only wonder what happens if a B4 lens is mounted on the body? All of those lenses (like the Digiprimes) are especially designed to match to the prism of the 3 chip beamsplitter. On a single chip camera there is no such thing like the beam spitter or a similar glass block. Cromatic apperations and color shifts can occur, so B4 is not just a smaller sized chip. It might be ok in SD but what about HD, 2K and 4K?
Is there anyone with information how this issue is handled?
Thanx

[Anders Holck]

The $3500 B4 mount contains corrective optics, not only to enlarge the pice 1.32 times, but also to correct for the the missing prisms in a single chip imager.

[Pig]

A [somewhat] related question: how good (or really, how POOR) would the image quality be, using older SD B4 lenses? We have several SD lenses laying around, and I'm just wondering whether to hang on to them or not.
I guess the question really is: is it worth spending $3500 on the B4 adapter and using it with SD lenses, or is it better to go the Canon/Nikon way (cheaper adaper/mount, and $3000 left over for some NICE lenses).

[Anders Holck]

Generally SD B4 lenses ca be sharp in the dead center, but absolutely suck in the corners. Softness and terrible abbreviations.
I think we have a good friend in Gibby, who has both a low Red reservation, is getting the B4 mount and has a lot of experience with B4 lenses.

If it's worth it depends on what you want to do with your red, If you shoot a lot o EFP/ENG type shots and need a nice motor zoom I guess it's worth it. Otherwise you will get the most bang or the buck with Nikon primes and the $500 mount. Not to mention the ability to utilize the full 4k resolution, where B4 is only filling the 2k/1080p res.

[Pig]

Thanks Anders. Yeah, that's what I thought. A shame the B4 mount is so expensive....well, I need to re-phrase that: A shame a B4 mount adapter has to be so complicated in order to work with a single chip cam.
regarding the B4 coverage: that's NO problem at all, that it doesn't cover 4k.
I plan not to shoot anything greater than 1080p anyway...for a LONG time.
Actually, thinking about that, I wonder how many WILL shoot 4k anyway. I mean it's GREAT to have, expecially re: future-proofing, but let's get real: how many here REALLY REALLY need anything ghigher than 1080p right now. Heck 720p or even SD is prefectly okay still, and my guess is that many will start off shooting 4k, then go down to 2k then settle at 1080p...at least for the time being.

[Anders Holck]

Incentives to shoot 4k is to get the 35mm DOF, 35mm FOV, a sharper image and still get Redcode RAW.
1080p is RGB only, 2k raw is cropped sensor only.
You can still shoot 1080p RGB scaled from the 4k sensor if you want.

[Pig]

Aha, yes, those are very good points!

[Blair S. Paulsen]

What I would really like to do is demo my current B4 SD lens on the adapter to see what the image looks like before I lay out $3,500. If I am unimpressed with the image I'll sell the lens then. It isn't likely to lose a ton of value in the next two months. Of course if you extend that period to two years, I expect all things SD will drop considerably.

[Steve Gibby]

This thread should probably be moved to the new EFP/ENG for RED forum.

I wouldn't use SD B4 2/3" lenses on RED One, even for 720p. IMO their MTF curves simply won't do justice to the potential of the RED One sensor.

As Anders mentioned, I'll be testing B4 2/3" HD ENG zooms on RED One, using the RED B4 adaptor. I'll post my impressions in the Lens Test forum and the EFP-ENG on RED forum.

B4 2/3" HD ENG lenses are expensive. If you already own them, and you'll be doing a lot of 1080p RGB production, then the RED B4 adapter makes great sense. If you don't already own those lenses, but want to do a lot of 1080p RGB production, then a used B4 2/3" HD ENG zoom is probably the way to go. If you search you can find those used 18x lenses, without doubler, for as little as $5,500 USD. You can always add in a wide converter on the front, and a 2x between the camera and lens to expand your capabilities with the lens.

[Bill Goehring]

Gibby

How about some specific ideas on where to find used HD Lenses?

[Steve Gibby]

Gibby

How about some specific ideas on where to find used HD Lenses?

Google searches, rental houses turning over their inventory (have your lens tech check them out before buying), EBay (be careful!), and private party online forum classifieds are a few ways...

[Bill Goehring]

Thanks for the suggestions but various permutations of Google Searches eg. HD Video Lenses, Broadcast HD Lenses, Used 2/3" HD Lenses, Canon HD Lenses, etc. come up empty.

The rental houses I can find on the net show only listings for rental lenses.

Ebay listings I can find are all 2/3" SD Lenses and less.

Don't know of any private party online forums.

The closest I could come was a Visual Products page for used video lenses: it's empty.

I'm out in the Northern Plains of South Dakota with no support or contacts, so any specific suggestions?

Thanks.

[Steve Gibby]

Billg,

I'd suggest you keep trying combinations of Google searches...

Here's an example of a large online motion media classified board that regularly has HD ENG zooms come up: http://www.mandy.com/1/class.cfm

There are many other equipment classified sites...keep looking and you'll find them...

Here's an example of one of the largest equipment rental firms that also has regular sales of former rental equipment: http://www.broadcastvideogear.com/

There are many other equipment rental companies...keep looking and you'll find them...

Many of the online cinematography and television forums have classified ads sections...search and you'll find them...

Hope this helps...

[Pig]

I wouldn't use SD B4 2/3" lenses on RED One, even for 720p. IMO their MTF curves simply won't do justice to the potential of the RED One sensor.

Yeah, I do understand that. It has been mentioned many times.
However, since the Red is SOOO superior to other offerings, what I'd like to establish is exactly how POOR the image really is going to be.
I'm still thinking, maybe erroneously, that a Red One with the B4 mount and a SD lens will produce perfectly okay results. No, not to its FULL potential, naturally, but acceptable nonetheless.
Of course whether this $3500 investment in the adapter is worth it ---> THAT is the big question, and I guess can only really be answered once we actually see results from a Red - SD B4 lens combo.

[tj williams]

Also: SD B4 lenses are different that HD B4 lenses so if the adapter is set up for HD lenses then there may be problems with your SD B4 lens. To prove this to yourself just mount your HD B4 lens on your SD Camera and compare the image with the SD lense?

[Michael Hastings]

What is different between the SD and HD - I'm not aware of any physical mount difference - one of my customers has been using both an SD wide angle and a HD lens on his Varicam for a while and I wasn't aware that he had do anything special to switch.

Initially most of the HD lenses were built from roughly the same components as the SD lenses and there was a real question if they were anything but hand selected components and tighter quality control. I am sure that optics have been upgraded lately, but maybe not as much as the price would indicate.



Also: SD B4 lenses are different that HD B4 lenses so if the adapter is set up for HD lenses then there may be problems with your SD B4 lens. To prove this to yourself just mount your HD B4 lens on your SD Camera and compare the image with the SD lense?

[Michael Brennan]

What is different between the SD and HD - I'm not aware of any physical mount difference - .

Mount is the same, but HD prisms have different physical dimensions to SD prisms.
The prism is designed in conjunction with lens design principles so as to aid lens manufacturers make long zooms, where the convergence of RGB wavelenghts to a equal distance is difficult. I'm told it is not commercially viable to make +25x zooms for film use for this reason.
100X lenses owe their performance to the help they get form the prism.


According to Fuji, the HD Prism is designed so red plane of focus is +10 microns further back and blue is +5 microns.

So HD lenses on SD cameras are not a perfect match nor are SD lenses on HD cameras.

Zeiss Bandpro have stated HD zoom lenses have almost twice the MTF of comparable film zooms.




Mickjoebill

[Brook Willard]

As per Gibby's request...